Thomas barton and thomas burns mcghie



UNIT D STATES THOMAS BARTON AND THOMAS BURNS MOGHIE, OF LONDON, ENGLAND.

PATENT OFFICE.

PROCESS OF REMOVING ZINC FROM LEAD.

SPECIFICATION forming part of Letters Patent NO. 689,27 5, dated December 1'7, 1901.

Application filed July 30, 1901. Serial No, 70,220. (No specimens.)

To a whom it may concern.-

Be it known that we,THoMAs BARTON, residing at No. 9 Gracechurch street, and THOMAS BURNs MOGHIE, residing at Normandy Wharf, Rotherhithe, London, England, subjects of the King of Great Britain, have invented a new and useful Process of Removing Zinc from Lead, of which the following is a specification.

Our invention relates to a new method of removing zinc from metallic lead.

Metallic lead, especially that desilverized by the aid of zinc in the well-known manner, is liable to contain considerable amounts of the latter metal. Our invention provides a simple method for removing the zinc. At the same time the bulk of the material used for the purpose may be recovered for future use.

In carrying our process into eifect we add to the molten metal, which may be contained in an ordinary steel or iron melting-pot and suitably inclosed, a small quantity of fused caustic alkali, preferably caustic soda, sufficient to cover the face of the molten metal. This alkali,which is at a temperature approximating to that of the fused metal, spreads over the face of the molten metal and immediately commences to act upon the zinc. For the purpose of quickening the action of the alkali a current of steam or steam and air may be blown into the pot of metal during the operation, effecting both mechanical and a chemical action thereon. In this case the alkali appears to act to some extent as a carrier of oxygen from the steam or air to the metallic zinc but the nature of the operation is not in any way changed thereby. The sus= pended zinc oxid either floats in the alkali or deposits therefrom, only small proportions remaining in the solution. Consequently when the molten alkali has been run ofi the surface of the lead the bulk of the zinc oxid in it can be readily dredged or filtered from the alkali and can be washed clear of caustic and finally pressed in a filter-press or otherwise prepared for use. The caustic alkali from which the Zinc oxid has been removed can be returned to the pot and used for another charge. The washings from the zinc oxid maybe evaporated and used over again as long as they contain a sulficient proportion of caustic alkali, and when carbonated by the action of the air or other-,

wise can be rendered caustic again in the well-known manner. There need, therefore, be very little loss of the reagent in the process.

What we claim is The hereinbefore-described process of purifying metallic lead, containing zinc, consistin g in heating the metals to the melting-point,

converting the zinc into a zinciferous product by the action of fused caustic alkali in the presence of oxygen,.and finally separating said zinciferous product from the lead.

In witness whereof we have hereunto set our hauds'in presence of two witnesses.

THOS. BARTON; H '1. BURNS MCGHIE.

Witnesses to Thomas Barton:

ARTHUR T. EBSWORTH, LEONARD E. HAYNES.

Witnesses to Thomas Burns McGhie:

ANDREW CowAN,

ANDREW FULTON. 

